Glaucoma is an eye disorder that afflicts many people and, if left untreated, can result impaired vision, and blindness. The disorder is characterized by progress optic neuropathy, often associated with high intraocular pressure (IOP) in the eye. The high IOP is caused by poor outflow of ocular fluid, the aqueous humor, from the anterior chamber behind the cornea. For most persons with glaucoma, the high IOP is caused by insufficient outflow of the aqueous humor from the anterior and posterior chambers of the eye due to the deterioration or blockage of the outflow route.
The focus of most treatments for glaucoma is in reducing the IOP. Conventional treatments for reducing IOP include medications, laser trabeculoplasty surgery, glaucoma filtration surgery and glaucoma shunt implantation surgeries. Many of the medications, including antimetabolites, reduce the formation of aqueous humor and have undesirable side-effects. In some glaucoma surgeries, an ophthalmic implant or shunt is implanted in the eye to facilitate drainage of the aqueous humor from the anterior chamber. Examples of such ophthalmic implants and a background discussion of glaucoma are disclosed by U.S. Pat. No. 5,520,631, U.S. Pat. No. 5,704,907, and U.S. Pat. No. 6,102,045, all granted to Nordquist et al., and all of which are hereby incorporated herein by reference.
These ophthalmic implants have, in some cases, provided an improvement in the drainage of aqueous humor from the anterior chamber, thereby reducing the IOP in the eyes of glaucoma patients and reducing the risk of vision loss. However, it has been observed that sometimes the implants are not as stable in the eye as would be ideal, so that they could migrate from their implanted position, resulting in the loss of efficacy and other complications. In addition, the implants are typically made of a porous material for permitting drainage through them. But the amount of drainage is limited by the fluid transport characteristics of the porous implant material in the cited devices.
Accordingly, a need remains in the art for a way to reduce IOP by implanting an ophthalmic implant that facilitates increased drainage of the aqueous humor fluid from the anterior chamber of the eye. In addition, there is a need for an ophthalmic implant and techniques for implanting it that result in the implant being more stable in the eye. Furthermore, there is a need for such an implant that is time and cost-effective to manufacture and implant. It is to the provision of such methods and articles that the present invention is primarily directed.